A Parasitic Wasp, in the garden yesterday feeding on pollen and nectar, is one what is thought to be the largest group of animals in the world- estimated at 2 million species. Parasitoids rather than true parasites (as they kill their hosts, albeit slowly) each species targets a specific host, whether ants, caterpillars, flies, bees, aphids, spiders or other insects. Most inject their eggs, which hatch and feed off the host at larvae or nymph stage. Many keep pests at bay in the garden and some are sold as biological controls, for farmers and gardeners. Conditions: Another dry day in tis worryingly dry spring. Temperature: Max 11- Min 9C.